/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.catalina.ssi;

import org.apache.catalina.util.IOTools;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;

/**
 * Implements the Server-side #exec command
 *
 * @author Bip Thelin
 * @author Amy Roh
 * @author Paul Speed
 * @author Dan Sandberg
 * @author David Becker
 */
public class SSIExec implements SSICommand {
	protected static final int BUFFER_SIZE = 1024;
	protected SSIInclude ssiInclude = new SSIInclude();

	/**
	 * @see SSICommand
	 */
	@Override
	public long process(SSIMediator ssiMediator, String commandName,
	                    String[] paramNames, String[] paramValues, PrintWriter writer) {
		long lastModified = 0;
		String configErrMsg = ssiMediator.getConfigErrMsg();
		String paramName = paramNames[0];
		String paramValue = paramValues[0];
		String substitutedValue = ssiMediator.substituteVariables(paramValue);
		if (paramName.equalsIgnoreCase("cgi")) {
			lastModified = ssiInclude.process(ssiMediator, "include",
					new String[]{"virtual"}, new String[]{substitutedValue},
					writer);
		} else if (paramName.equalsIgnoreCase("cmd")) {
			boolean foundProgram = false;
			try {
				Runtime rt = Runtime.getRuntime();
				Process proc = rt.exec(substitutedValue);
				foundProgram = true;
				BufferedReader stdOutReader = new BufferedReader(
						new InputStreamReader(proc.getInputStream()));
				BufferedReader stdErrReader = new BufferedReader(
						new InputStreamReader(proc.getErrorStream()));
				char[] buf = new char[BUFFER_SIZE];
				IOTools.flow(stdErrReader, writer, buf);
				IOTools.flow(stdOutReader, writer, buf);
				proc.waitFor();
				lastModified = System.currentTimeMillis();
			} catch (InterruptedException e) {
				ssiMediator.log("Couldn't exec file: " + substitutedValue, e);
				writer.write(configErrMsg);
			} catch (IOException e) {
				if (!foundProgram) {
					//apache doesn't output an error message if it can't find
					// a program
				}
				ssiMediator.log("Couldn't exec file: " + substitutedValue, e);
			}
		}
		return lastModified;
	}
}